Newsletter Vol 23 Issue 3, 2015 – California Invasive Plant Council

Vol. 23, No. 3

Fall 2015

Cal-IPC News
Protecting California’s Natural Areas from Wildland Weeds
Newsletter of the California Invasive Plant Council

Going to

great lengths

Treating fennel on San Clemente
Island. Winner of the 2015 Photo
Contest, by Aaron Echols, Channel
Islands Restoration

EDRR in Bay Area National Parks 4
Symposium photos 6
Does glyphosate cause cancer? 8
Do No Harm 9
Puncturevine attacks! 10
Scotch broom mite to the rescue 11
EMAPi in Hawai’i 13
Habitat conservation planning 14

From the Director’s Desk

It’s the little things…
Cal-IPC
1442-A Walnut Street, #462
Berkeley, CA 94709
ph (510) 843-3902 fax (510) 217-3500
www.cal-ipc.org info@cal-ipc.org

Protecting California’s lands and waters
from invasive plants
STAFF
Doug Johnson, Executive Director
Elizabeth Brusati, Senior Scientist
Agustín Luna, Director of Finance & Administration
Bertha McKinley, Program Assistant
Dana Morawitz, Program Manager
for GIS and Regional Conservation
BOARD OF DIRECTORS
Jason Casanova, President
Council for Watershed Health
Jennifer Funk, Vice-President
Chapman University
Steve Schoenig, Treasurer
Independent Consultant
Jutta Burger, Secretary
Irvine Ranch Conservancy
Morgan Ball
Wildlands Conservation Science
Tim Buonaccorsi
RECON Environmental, Inc.
Gina Darin
California Department of Water Resources
Jason Giessow
Dendra, Inc.
Elise Gornish
UC Davis, Dept. of Plant Sciences
Shawn Kelly
Southern California Wetlands Recovery Project
Drew Kerr
Invasive Spartina Project
Ed King
Placer Co. Ag. Commissioner’s Office
Annabelle Kleist
Capitol Impact
Dan Knapp
American Conservation Experience
John Knapp
The Nature Conservancy

STUDENT LIAISONS
Marina LaForgia
UC Davis
Justin Valliere
UC Riverside

Affiliations for identification purposes only.

Cal-IPC News
Fall 2015 – Vol. 23, No. 3

Editors: Doug Johnson & Elizabeth Brusati
Published by the California Invasive Plant Council. Articles may
be reprinted with permission. Previous issues are archived at
www.cal-ipc.org. Mention of commercial products does not
imply endorsement by Cal-IPC. Submissions are welcome. We
reserve the right to edit content.

Cal-IPC News Fall 2015

By Executive Director Doug Johnson

ometimes small changes can result in significant progress. A new sentence in a
planning document may provide a stronger foundation for programmatic policies.
Here are a few small improvements made recently that hold promise for helping our
work in the future.
The California Dept. of Water Resources recently updated its model ordinance for
Water Efficient Landscaping. This serves as a template for local jurisdictions to use
in setting local policy. Now included under landscape design: “The use of invasive
plant species, such as those listed by the California Invasive Plant Council, is strongly
discouraged.” We have received calls from municipalities wanting guidance on using
our list, and we are working with Alameda County StopWaste on developing guidelines
for using our list in making appropriate site-specific landscaping decisions.
Along the same lines, California is updating its General Plan Guidelines for communities. Cal-IPC Member Paul Minault is following the process and providing formal
comment on ways to include invasive plant management, for instance in the section on
protecting open space for habitat and conservation.
The National Green Building Standard is in revision, including a brief section
on non-invasive landscaping. A project loses significant points if it cannot claim to
be using non-invasive vegetation (and a project can earn extra points for removing
invasives found on site). New draft language clarifies that invasive plant lists are not
limited to those from a government agency.
This elevates the potential for using other
science-based lists from organizations like
Cal-IPC.
California recently completed the 2015
Update to its Wildlife Action Plan. Tabular
presentation of 29 ecological pressures
considered in the statewide stakeholder process show that invasive species are the top
ecological pressure on wildlife by far, with
50% more strategic actions proposed than
the next runner up (“livestock, farming, and
ranching”). Though the plan does not call
this out explicitly in the text, the evidence
is there, and groups dedicated to protecting
wildlife can’t miss the significance.
Only time will tell, but with luck these
small bits of progress will add up to big
progress in the future.

California Water Efficient Landscaping model ordinance:
www.water.ca.gov/wateruseefficiency/landscapeordinance
California General Plan Guidelines: www.opr.ca.gov/s_generalplanguidelines.php
National Green Building Standard: www.homeinnovation.com/ngbs
California Wildlife Action Plan: www.wildlife.ca.gov/SWAP

Cal-IPC Updates
Desktop WHIPPET. The WHIPPET
tool helps land managers prioritize populations of invasive plants for eradication.
Last year an online version was released
by Cal-IPC. Gina Darin of the CA Dept.
of Water Resources has completed a
new-and-improved version of the desktop
version that you can use with your own
ArcGIS for greater ability to customize the
analysis Download from whippet.cal-ipc.
org.
Herbicide BMPs. Our manual of “Best
Management Practices for Wildland
Stewardship: Protecting Wildlife When
Using Herbicides for Invasive Plant
Management” includes practices to reduce
risks to wildlife. Toxicology charts show
risks of commonly used herbicides to
different type of wildlife. Download from
www.cal-ipc.org.
Regional proposals. We worked with
partners in three more regions—South
Central Coast (Santa Barbara and San
Luis Obispo counties), North Central
(Shasta, Siskiyou, and Trinity counties),
and San Mateo County (for Canary Island
St. Johnswort)—to submit proposals to
the California Wildlife Conservation
Board to eradicate high-priority invasive
plant species.
Getting around. Cal-IPC has presented on our work at the State of the
San Francisco Estuary conference in
Oakland, the Southwest Climate Summit
in Sacramento, and at the international

Wildland
Weed News

SF Bay Upland Habitat Goals. The
regional goals document has been
updated. Cal-IPC contributed to chapters
on “Connections to the Watersheds”
and Wildlife. baylandsgoals.org/
science-update-2015/

EMAPi conference in Hawai’i (see p. 13).

Weeds hurt sage grouse. The Westsern
Association of Fish & Wildlife Agencies
produced a report on Invasive Plant
Management and Greater Sage-Grouse
Conservation as part of the run-up to the
recent decision to not list the Great Basin

Upcoming project. We received a twoyear grant from the National Fish and
Wildlife Foundation to remove Algerian
sea lavender from marshes around San
Francisco Bay and
to develop an index
for ranking the
level of invasive
plant threat to each
salt marsh.

Other News
Using livestock
to control weeds.
University
of Nevada
Cooperative
Extension has designed a handbook
for using livestock
for noxious weed
Wall of Arundo. Second place in 2015 Photo Contest, by Sloane
control in nine
Seferyn, UltaSystems Environmental, Inc.
Western states.
The guide includes
detailed information
species as endangered. www.doi.gov
on 26 weed species and is available as a
free download. www.webpages.uidaho.edu/ CISM closes. After 15 years as a successful western regional hub for invasive
rx-grazing/Guidelines.htm
species expertise and interagency project
Educational books. Teaching About
collaboration, the Center for Invasive
Invasive Species is designed for youth
Species Management closed its doors June
educators, with 11 units and 20 ready-to- 30 due to loss of funding. Their website
use activities on invasive species (www.
serves as an archive of CISM’s projects
greenteacher.com). Outlaw Weeds of the
and resources. www.weedcenter.org
West has descriptions of invasive plants in
western states, plus cartoons, photos, and
botanical drawings to capture children’s
interest, ages 8-12. www.mountain-press.
Keep current!
com.
Remember to check your Cal-IPC
State Wildlife Action Plan released. The
membership status on the mailing
2015 revision of California’s Plan is now
label of this newsletter. Keep your
available. The SWAP describes challenges
membership current so you don’t miss
faced by wildlife and proposes actions for
out on any of the new happenings in
each eco-region of California. Invasive
the field. You can renew online or with
species are listed more often than any
the enclosed envelope. Thank you for
other threat. Cal-IPC wrote the appendix
your membership and the support it
on Invasive Species. www.wildlife.ca.gov/
provides for our work!
SWAP

Cal-IPC News Fall 2015

Early Detection in Bay Area National Parks
By Eric Wrubel, San Francisco Bay Area National Parks

he Invasive Plant Species Early
Detection (ISED) program of the
San Francisco Bay Area National Parks
Network (SFAN) was
developed to locate
new infestations of
invasive plants before
they become widely
established in network
parks. Prevention is
the first line of defense
against biological invasions. However, when
preventative measures
are not successful, early
detection and rapid
response (EDRR) is
the most efficient and
cost effective strategy
to reduce the harmful
impacts of invasive
species.

uncommon in SFAN parks, or are
located in adjacent lands, that would
cause ecological or economic impacts

management. The SFAN Inventory and
Monitoring Program has published and
implemented a detailed early detection
protocol to promote EDRR in the parks
(Williams et al. 2009).

during surveys, and communicate
findings quickly to park vegetation
managers.

A prioritization matrix was developed
to rank species for early detection, based
on current knowledge. Species ranked
high if any of the
following were true:
– they are invasive in
California
– they are ecosystem
alterers (effecting major
changes to chemical or
physical processes in
ecosystems)
– they endanger rare
plants
– their known acreage
in the parks was low,
and their feasibility of
control was high.

Surveys are
conducted on foot by
ISED teams of two
The SFAN parks
to four trained staff
Early detection intern Lindsay Ringer removes foxglove (Digitalis purpurea) at
include Golden Gate
members,
interns,
Rodeo Lagoon in the Golden Gate National Recreation Area. Photo by Kevin
National Recreation
and
volunteers.
The
Sherrill.
Area, John Muir
protocol
focuses
on
National Historic
roads
and
trails
because
Site, Pinnacles National Monument, and
they are primary pathways for the estabif they were to become established.
Point Reyes National Seashore. These
protected areas are critical for conserva2. Rank park subwatersheds by resource lishment and spread of invasive plants.
The highest priority target species are
tion of the endemic flora and fauna of
value and risk of invasion. Survey all
mapped with the greatest level of detail,
Central California, a global biodiversity
roads and trails in each park within a
while medium and low priority species are
hotspot. Due to their close proximity to
five year survey cycle, with top priormapped with decreasing levels of detail.
major metropolitan areas, SFAN parks
ity subwatersheds surveyed annually,
are also vulnerable to biological invasions
moderate priority surveyed biennially, ISED teams also implement manual
through numerous pathways, and are
and low priority surveyed once within treatments to remove small populations of
high priority species, when treatment time
heavily impacted by invasive plants, with
five years. Assess and map target
will not exceed 10% of survey hours.
over 90 invasive species under active
invasive plant populations detected

Early detection protocol
The following objectives form the
framework of the ISED protocol:
1. Develop a priority list of target
invasive plant species that are

Cal-IPC News Fall 2015

3. Evaluate data after each five year
survey cycle to determine the distribution of target invasive species along
roads and trails in each park, and
identify possible management actions
to prevent new infestations. Use the
data to refine subwatershed rankings
for search priority and timing.

Outreach and collaboration
The ISED program was designed as
an early warning system that accommodates information inputs from a diverse
network of observers. Detailed data
from protocol-level surveys document
abundance or absence of target species in
survey areas. Opportunistic observations
are also encouraged in order to increase
the probability of detecting uncommon invasive plants at an early stage of

establishment. We receive early detection
reports from volunteers, park staff, park
partners, weed management areas, and
local resource management agencies.
Although these reports are not used in
data analysis, they often alert us to newly
introduced species, or new locations
of target species. The ISED program
provides plant identification products
and services, and conducts formal and
informal trainings, to increase awareness
of new invaders in network parks.

ISED program produces a monthly
email newsletter, Early Detection News,
documenting significant new occurrences
and survey results, and publishes annual
reports on the NPS Natural Resources
Publication Management website (www.
nature.nps.gov/publications/nrpm). The
ISED program also collaborates with
regional and statewide organizations such
as the Bay Area Early Detection Network,
county-based Weed Management Areas,
California State Parks, and Cal-IPC.

Reliance on data collected by volunteers has evolved over the course of the
program. Initially, volunteers from the
general public were recruited and trained,
in the hope that they would become
advanced observers capable of conducting independent protocol-level surveys.
However, low recruitment and retention
rates, and marginal data quality led us

Data, results and future directions

Since its inception, the ISED program
has been involved in the development
of innovative tools to collect and share
invasive plant data. The GeoWeed
geospatial database and mapping system, a
modification of The Nature Conservancy’s
Weed Information Management System
(WIMS), was developed in partnership
with the
Sonoma
Ecology
Center
in 2007.
In 2012
the SFAN
Inventory
and
Monitoring
Program
partnered
with Calflora
and a
coalition
of resource
management
agencies
to create
Early detection interns Kris Daum and Raphaela Floreani Buzbee
the Weed
remove kangaroo apple (Solanum aviculare) at Point Reyes National
Manager
Seashore. Photo by Nick Stevenson, NPS.
system,
which was
to abandon this approach. Reportable
launched in 2015. Weed Manager is
data is collected by staff and interns, who
hosted on Calflora.org, the most compreare generally able to invest more time to
hensive statewide repository for informadevelop the skills necessary to identify and
tion on native and naturalized plants in
map target species which are often cryptic.
California. Based in part on the GeoWeed
Monthly reporting and communicadata model, Weed Manager tracks invasive
tion with a network of weed workers
plant occurrences, assessments and
creates an information feedback loop
treatments (OATs) through time. Mobile
that enhances the effectiveness of early
platforms such as tablets and smartphones
detection efforts, and increases awareare utilized for mapping and data colness of new invasive species threats. The
lection, and web-based applications are

used for data import, export, editing, and
analysis. Weed Manager allows unprecedented opportunities for data sharing
between users, while also providing robust
privacy tools, making it an ideal platform
for storing and disseminating early detection data.
The ISED program has mapped over
8,000 infestations of target invasive plant
species since 2008, and removed over
1,000 of these infestations. ISED has also
discovered over 50 non-native species
not previously known to occur in SFAN
parks. Network parks actively integrate
ISED data into invasive plant management and planning, which has led to the
initiation of control efforts for species
in the early stages of invasion, such as
stinkwort (Dittrichia graveolens), mayten
(Maytenus boaria), Andean tussockgrass
(Stipa manicata), and others.
Evaluation of data from the first fiveyear survey cycle suggests refinements for
search priority and timing. The current
detection rate of approximately 1,500
new patches per year exceeds the response
capabilities of park programs. The survey
frequency may now be reduced to come
into balance with treatment rates, since we
have comprehensive distribution information from over five years of high-frequency surveys. We also hope to improve
the linkage of early detection data with
treatment data from other programs to
better assess the effectiveness of EDRR as
a unified management strategy.

Resources
Williams, A. E., S. O’Neil, E. Speith,
and J. Rodgers. 2009. Early detection of
invasive plant species in the San Francisco
Bay Area Network: A volunteer-based
approach. Natural Resource Report NPS/
SFAN/NRR—2009/136. National Park
Service, Fort Collins, Colorado.
Newsletters available at: www.sfnps.org/
weed_watchers/newsletters
To subscribe to Early Detection News,
email eric_wrubel@nps.gov
Calflora Weed Manager: www.calflora.
org/entry/weed-mgr.html

Cal-IPC News Fall 2015

2015 Cal-IPC Symposium

Photo Drew Kerr

…in sunny San Diego!
Over three hundred land managers, researchers and volunteers came to our 24th annual
event, including attendees from Baja California, Italy, France, and Oman. This year’s
Symposium featured special sessions on how invasive plant management can be incorporated
into habitat conservation planning. A closing panel on the future of invasive plant management stimulated discussion on research needs, new technology, cross-border collaboration,
and finding new funding. Presentations are posted at: www.cal-ipc.org/symposia/archive
Congratulations to this year’s award winners!
Jake Sigg Award for Vision and Service: Cindy Burrascano, San Diego CNPS [top right,
with Doug Johnson and Mike Kelly]
Golden Weed Wrench for Land Manager of the Year: Bill Neill, Riparian Repairs [middle
right, with Doug Johnson and Jason Casanova]
Organization of the Year: Urban Corps of San Diego County [bottom left, Doug Johnson;
Robert Chavez; corpsmembers Tanya Sanchez, William Beaven, and Ismael Solis; and Cal-IPC
board member Dan Knapp (second from right).
Weedzilla for National Park Service Land Manager of the Year: Clark Cowan, Channel
Islands National Park [bottom right, with Bobbi Simpson and Irina Irvine]
Student Papers: 1st Justin Valliere, UC Riverside; 2nd Ellen Esch, UC San Diego; 3rd
Cody Ender, Sonoma State University
Student Posters: 1st Kerstin Kalchmayr, San Francisco State University; 2nd Annika
Rose-Person, UC Santa Cruz; 3rd Julia Michaels, UC Davis

Cal-IPC News Fall 2015

The poster session featured 23 presenters. Here, Julia
Michaels of UC Davis talks about her work measuring
impacts of grazing on vernal pools. Photo JP Marie.

Trish Smith of The Nature Conservancy leads a panel of experts on habitat
conservation planning in discussion about how regional plans can incorporate
invasive plant management to protect habitat for listed species. Photo Drew Kerr.

Field trips took attendees to the Cleveland National Forest (not pictured), Rancho Jamul Ecological Reserve (left), and Black Mountain Open
Space for a drone mapping demonstration by The Nature Conservancy’s Brian Cohen (right). Photos Dana Morawitz, Elizabeth Brusati

The raffle and social hour provided time to relax with fellow
attendees and support Cal-IPC’s work. Photo JP Marie.

Mickie embraces Bromus carinatus and promises everything will be OK.
Photo Contest 3rd Place, Melanie Dickinson, Younger Lagoon Reserve.

Mark your calendars for Cal-IPC’s 25th Symposium, Tenaya Lodge, Yosemite, Nov. 2-5, 2016!
Cal-IPC News Fall 2015

Is glyphosate a carcinogen?
(And is that the most important question for land managers to ask?)
By Joel Trumbo, California Department of Fish and Wildlife

the judgment of the reviewing pathologists was that the kidney tumors were not
treatment-related. The IARC pathologists,
however, did not agree with the US EPA’s
conclusion and included the study with
its original conclusions in their 2015
assessment.

his past May, the International
Agency for Research on Cancer
(IARC) made a determination that
glyphosate—the active ingredient in
Roundup® and other similar herbicide
products—is probably a human carcinogen. IARC placed the herbicide in its 2A
“probable human carcinogen” group along
with other synthetic compounds such as
the insecticide malathion (and other risks
such as UV light and red meat). IARC’s
determination was based on “limited
evidence of carcinogenicity in humans
and sufficient evidence of carcinogenicity
in experimental animals.”
In response to the IARC decision, Cal
EPA’s Office of Environmental Health
Hazard Assessment (OEHHA) published
a notice announcing its intent to list the
herbicide as a carcinogen under the Safe
Drinking Water and Toxic Enforcement
Act of 1986 (Prop 65). The comment
period for this decision closed this past
October 20. OEHHA’s decision is
forthcoming.
Reaction to the IARC determination
and the potential Prop 65 listing was
significant. People on both sides of the
fence—pesticide advocates and pesticide
opponents–were asking, Should we stop
using glyphosate? In order to answer this
question, it’s valuable to consider the
following.
First, IARC’s determination of “limited evidence” of human carcinogenicity
was based on information provided by
epidemiological studies. These studies
used questionnaires given to farmers
and their families in North America and
Europe to look for a link between chemical exposure and cancer. Epidemiological
studies can reveal if there’s a positive
association, or correlation, between
exposure to the agent and cancer, but they
cannot be used to determine the cause of
the cancers. They also cannot completely
rule out other explanations such as chance

Cal-IPC News Fall 2015

Prop 65 Warning Sign: One important
disadvantage of this sign is that it alerts
one to the presence of a carcinogen or
reproductive toxicant, but it provides no
information on the level of exposure that
would actually put you at risk.
or bias. Additionally, these studies have
limitations such as the accuracy of selfreported information and the effect that
exposure to other substances, including
other pesticides, might have on cancer
incidence. In short, these types of studies
can identify a correlation, but they don’t
establish a direct link or causality.
IARC’s determination was also based
on “sufficient evidence” of carcinogenicity in lab animals, but not all of the
studies in the assessment revealed a
carcinogenic link. Only four of the seven
chronic feeding studies used in the IARC
assessment found a relationship between
glyphosate and cancer. One of those
studies—a 24-month feeding study where
kidney tumors in mice were initially
determined to be glyphosate-related—was
re-evaluated by the US EPA in 1991 and

Toxicological risks must be assessed
by looking not only at toxicity—in
this case carcinogenicity—but also at
exposure. This assessment cannot be
made solely by asking the question, Is the
substance a carcinogen? While several of
the animal feeding studies in the IARC
assessment demonstrated a positive relationship between glyphosate exposure and
cancer, the concentrations in those tests
were higher than what an herbicide applicator would experience in the field. Even
if one ignores the fact that oral exposures
are highly improbable for applicators, the
dosages themselves are atypical for actual
herbicide use scenarios. Depending on the
study that’s examined, the tumor-causing
dosages were from 30 to 30,000 ppm.
Using these dosages, a man weighing 175
pounds would have to drink more than a
quarter tablespoon to slightly more than 1
gallon of herbicide every day for 2 years
to have an exposure that’s equivalent to
that of the lab animals’.
As more research is done, it’s a certainty that many more substances, some
of which we are commonly exposed to in
everyday life, will be identified as carcinogens. The recent inclusion of bacon and
other processed meats on IARC’s Group
I list for known human carcinogens is
evidence of this. When considering these
types of determinations, it’s critical to
remember that the amount and duration
of exposure must also be considered,
not just the fact that the chemical made
it “on the list.” Perhaps the best advice
regarding this fact can be found on the
…continued page 9

“Do No Harm” to avoid introducing pests in restoration
By Elise Gornish, UC Davis

cological restoration is integral for the
reestablishment of functional plant
communities in degraded systems across
California. Restoration often involves the
transplanting of nursery stock or fieldcollected plants into damaged habitat,
and this movement of plant materials can
sometimes result in unintended transfer
of plant pathogens, pests and diseases into
previously uninfected habitats. As you are
probably aware, this has become a critical
issue in the wake of several inadvertent
introductions of Phytophthora ramorum,
the pathogen causing Sudden Oak Death,
through contaminated native plant stock
from nurseries.
To address this unintended consequence of ecological restoration activities,
UC Cooperative Extension Specialists
Elise Gornish and Travis Bean organized
the first annual Do No Harm workshop
(http://donoharm.ucdavis.edu), held at
the UC Palm Desert campus on Nov. 5,
2015. The day-long workshop featured
a series of poster and oral presentations
that focused on identifying, preventing
and mitigating the spread of pests, plant
pathogens and diseases through ecological
restoration activities in California. The
event was extremely successful, with over
70 attendees affiliated with a diversity
of groups, including federal agencies,

…glyphsosate continued
website of the American Cancer Society:
“Even if a substance or exposure is known
or suspected to cause cancer, this does
not necessarily mean that it can or should
be avoided at all costs. For example,
estrogen is a known carcinogen that
occurs naturally in the body. Exposure to
ultraviolet (UV) radiation from sunlight
is also known to cause cancer, but it’s
not practical (or advisable) to completely
avoid the sun.”

academic institutions, native plant
nurseries, and restoration practitioner
organizations.

The CNPS Santa Clara Valley Chapter
has posted several YouTube videos on
avoiding the spread of Phytophthora:

The dynamic group of presenters
featured researchers from all over the
state, and presentations covered a range of
topics, including: historical perspectives
on California restoration; soil biology and
restoration; plant and pest invasion in
California; Phytophthora in native areas;
and mitigating movement of Phytophthora
in native nurseries. Most of the presentations will be available on the workshop
website in the near future. In addition
to formal presentations, the workshop
provided opportunities for networking
and collaboration initiation through
discussion panels and coffee breaks.
The workshop closed with all attendees
completing a survey that was designed
to collect information about unintended
consequences of activities associated with
ecological restoration.

www.youtube.com/
watch?v=CuPYc9lcCcc
www.youtube.com/
watch?v=oKEQqDBU3vw
www.youtube.com/
watch?v=lMw4NpDgCTs

University of Wisconsin press. We look
forward to organizing the second annual
Do No Harm workshop, which will focus
on addressing another aspect of ecological
restoration in California. The workshop is
tentatively scheduled for November 2016
in Davis. Stay tuned for an announcement in Cal-IPC News.

Many diverse sponsors helped make
the workshop possible: UC Riverside and
UC Davis, UC Division of Agriculture
and Natural Resources, the Center for
Conservation Biology, the Watershed
Nursery, the Riverside-Corona Resource
Conservation District, the California
Invasive Plant Council, the UC Weed
Research & Information Center, and the

using glyphosate?, the answer leads us
back to exposure. If exposure is low, risk
will also be low. In the final analysis, this
means that there’s no good reason to stop
using glyphosate whether it’s a carcinogen
or not.
Joel Trumbo is a Senior Environmental
Scientist with the California Department
of Fish and Wildlife. Joel has been the
statewide Integrated Pest Management
Coordinator for CDFW since 1990.
Contact him at Joel.Trumbo@wildlife.
ca.gov.

As to the question, should we stop

Cal-IPC News Fall 2015

Is it just me, or is puncturevine everywhere this year?
By Jennifer Gibson, Ecologist, Whiskeytown National Recreation Area

es, puncturevine (Tribulus terrestris),
a.k.a. “goat head” or “caltrop” (or
“scourge of summer” by kids on bikes
everywhere because the thorny seed heads
puncture bike tires with ease). The name
“caltrop” comes from the spiked metal
devices designed to impede advancing
armies in medieval times. Besides injury,
the burs can also be toxic to sheep and
cattle, causing nitrate poisoning.
This summer, when I went running
on the same trails I’ve run on since high
school in my favorite Bay Area park –
Sycamore Grove near Livermore – there
it was, crawling onto park property from
an adjacent vineyard in giant sprawling
mats. I know this plant well. We’ve been
treating a well-established population up
at Whiskeytown National Recreation Area
where I work in northern California for
ten years now, and it takes back-to-back
treatments (sometimes 5-6 mechanical
and chemical treatments) and monitoring
every summer to keep it from going to
seed. And now I find carpets of the stuff
moving into my favorite park in the Bay
Area! It’s in the horse trailer parking lot
where people unload saddles, blankets and
gear; the main parking lot with strollers,
bikes, dogs, and little kids; and radiating
out from these areas along trails.
What’s worse is that when I drove back
to Shasta County, I found it everywhere
as well; in front of the Volunteer Fire
Department, around the elementary
school’s soccer field, on paths at the State
Historic Park, and at the new open space
dog park along the Sacramento River. I
even found new infestations popping up
at trailheads and developed areas in my
park. And you know that the seeds are
hitching a ride on visitors to these sites
back to people’s backyards, neighborhoods, and other uninfested parks and
recreation areas.
I had to ask myself, “Has it always
been like this? Is anyone tracking puncturevine? How did it get so out of hand?”
The good news is that it is a poor

Cal-IPC News Fall 2015

competitor and not a prolific seed producer, when compared to other noxious
weeds. And, new infestations can be
easily controlled by hand pulling before
the burs begin to form. Other suggestions
for control include planting vegetation
that can out-compete puncturevine.
The bad news is that it seems to thrive
in drought conditions, which may be why
it appears to be spreading throughout
California the past few years. And the
other bit of bad news is that I spoke with
several parks affected by this plant and
even though this species can be relatively
easy to treat, most land managers are
woefully underfunded and understaffed to
tackle this unanticipated problem.
On the lighter side, online searches
were entertaining. You can buy “Ouchless
Faux-Paws” to protect your pet’s feet from
puncturevine. In Oregon, you can buy
puncturevine weevils to use as biocontrol
(for every 10 units of weevils purchased,
you get a free 1964 silver Kennedy
half-dollar!) There’s “I Hate Goat Head”
apparel, videos, rants from bicyclists, volunteer work weekends and even bounties
placed on each garbage bag stuffed with
dead plants. It’s a relief to know that I’m
not alone – this plant is universally hated.
However, even though puncturevine
is C-rated by the California Department
of Food and Agriculture, it is not listed in
the Cal-IPC Online Inventory – mostly

because it is not common in wildlands
and is more typically found in urban or
agricultural areas and roadsides. I have
to agree with this – I don’t see this plant
adversely affecting native biodiversity in
wildlands. But I do see it in parks and
open spaces. So, as a land manager of a
National Recreation Area that’s focused
on preserving and protecting native plant
communities while also promoting hiking, biking and positive visitor experience,
it is at the top of my “Most Wanted” list
of weeds to manage.
Would a Cal-IPC listing help? I think
so. The more public outreach and education, the better. The Online Inventory is
not just for land managers and academics; it is used by volunteers, planners,
and concerned citizens. Providing an
assessment of the ecological impacts
of puncturevine would help managers
control the species and help the public
understand how to prevent spread. And
the good news is that even though getting
this plant under control is a lot of work, I
think it can be done. Particularly if we can
treat the parks and recreation areas where
the seeds are most likely to adhere to little
kids’ shoes, bike tires and paws, and then
later be dispersed and spread elsewhere.
And if Cal-IPC needs a universally-hated
plant to rally support for common cause
amongst diverse user groups – then
puncturevine is definitely our plant!
The best thing about this story is that
after I drafted this article, I found myself
back on the running trails at Sycamore
Grove and I did not see a single puncturevine plant. Zero. Nada. I was beginning to think I imagined the thousands of
plants sprawling out from the parking lot
and along the roads and trails. I emailed
the park and found out that yes, the plant
really exploded on them this year, but
park staff and volunteers to hand pull it
throughout the park. So, it is possible to
get a handle on it! I know there needs
to be follow-up, but congratulations to
Sycamore Grove for setting the example
and taking care of their park!

Scotch broom gall mite: a new partner in broom management
By Scott Oneto, Farm Advisor, UC Cooperative Extension, Central Sierra

recent find in El Dorado County has
weed scientists, land managers, foresters, botanists, and plant conservationists
throughout Northern California very
excited over a tiny mite.
The broom gall mite has recently
been observed attacking the invasive
plant Scotch broom (Cytisus scoparius) in
California’s natural landscapes. Scotch
broom, desired for its bright yellow flowers and rapid growth, was first introduced
into North America as an ornamental and
for erosion control. However, its ability to
outcompete native plants and form dense
stands has also made it one of California’s
worst wildland weeds.
The mites cause galls, small abnormal
growths on the plant’s buds, to form
during feeding, greatly reducing Scotch
broom’s ability to grow and reproduce.
This mite is considered to be an ideal
biological control agent due to its specialized feeding habits and the debilitating
damage it can cause to invasive weeds. In
some areas, the gall mite has already killed
large stands of broom.

The mighty mite
The Scotch broom gall mite, more
closely related to spiders and ticks than
insects, is a type of eriophyid mite that is
nearly invisible to the naked eye, measuring roughly the width of a human hair.
Although the mite is tiny, the galls formed
by plants in response to the mite’s feeding
are quite noticeable. The small fuzzy
masses occur along the length of the stem
and can be numerous.
Native to Europe, the mite was first
found on Scotch broom in the Tacoma,
Washington, and Portland, Oregon,
regions in 2005. (It was not introduced as
a formal biocontrol, and how it got there
remains a mystery.) Since that time the
mite has become established throughout
western Washington and Oregon and
even into parts of British Columbia. The
mite is very host-specific and has not been
found on other broom species, such as

French or Spanish broom. Up until 2013,
the mite had only been found as far south
as Ashland, Oregon, with no occurrences
in California.

and other agencies spend a considerable
amount of time and taxpayer money each
year treating Scotch broom plants either

However in
March 2014, a landowner in El Dorado
County brought a
sickly looking Scotch
broom plant to the
local U.S. Forest
Service (USFS)
office to examine
small growths on the
branches. Farm advisors in the University
of California
Cooperative
Extension’s (UCCE)
El Dorado County
office have been
monitoring this
mite’s spread
throughout the
Pacific Northwest
for the past few years
and identified the
sample as a potential
gall mite.
Since the first
detection in El
Dorado County,
Galls on scotch broom. Photo by Scott Oneto.
USFS, UCCE, and
the California Department of Food and
by applying herbicides or prying them up
Agriculture have been on the lookout
by the root. With the mites’ help, we’ll
for other occurrences of the gall mite on
make much greater progress toward reducScotch broom. Surprisingly, the mite has
ing Scotch broom infestations.
since been found in many areas throughHelp us track the spread of this
out El Dorado, Placer, and Nevada
beneficial
mite. If you see evidence of
counties; but how it got there is a mystery.
Scotch
broom
gall mites, report it on
Mites are known to travel long distances
the
UC
Cooperative
Extension website:
using wind currents and by hitching rides
ucanr.edu/broomgallmite.
on animals, humans and equipment. It
For more information about Scotch
is likely that many more finds will be
broom and other brooms, read UC IPM’s
forthcoming.
Pest Note: Brooms at www.ipm.ucdavis.
Scotch broom currently infests
edu/PMG/PESTNOTES/pn74147.html.
millions of acres throughout California,
Contact Scott at sroneto@ucanr.edu.
causing loss of native plant biodiversity
and an increased fire risk. The USFS

Cal-IPC News Fall 2015

Might wood rats be allies in broom
management?
In Marin County’s oak-bay-madrone forests, it’s common
to see sizable wood rat middens, the piles of sticks and
leaves they build to live in, near stands of mature French
broom (photo below). Broom growing near these middens
often has bark missing around the base of the stems and on
parts of the upper stems as a result of herbivory (photo at
left). While the bark removal does not appear to kill the
plants, it does appear to weaken them and could potentially
cause mortality in conjunction with other factors, particularly intense sunlight and drought. In addition, some
mature broom stands have very few seedlings. Might wood
rats be consuming a significant portion of the seed bank?
This may be a question worth researching.
-Paul Minault

Dredging for Hydrilla tubers
Hydrilla verticillata is one of the world’s worst aquatic weeds. Introduced into
Florida from Sri Lanka through the aquarium trade in the 1950s or 1960s, it
had infested 100,000 acres by 1994 with presence in 80% of the the state’s lakes
and rivers. The plant is now actively managed by the Florida Fish & Wildlife
Conservation Commission at a cost of $20-35 million each year.
Hydrilla grows quickly, doubling size in 2 weeks, and it spreads easily through
fragments and tubers, which can survive for 4-7 years in sediments where they
are hard to reach. Besides the aquarium trade, the plant can be introduced via
infested water lily bulbs and warm-water fish stocking. USDA has listed hydrilla
as a federal noxious weed.
In California, hydrilla first appeared in 1976 in Yuba County. It has also been
found in Clear Lake, a major recreational boating destination. In partnership
with the California Dept. of Water Resources, the California Dept. of Food and
Agriculture (CDFA) maintains a program working to eradicate hydrilla from the
state. Clear Lake is a primary target because of its proximity to the Delta, but
ditches in Yuba County remains an important front because spread could impede
agricultural irrigation. Small-scale mining equipment is used to dredge for tubers
(right), and then irrigation channels are lined with concrete.
-David Kratville, CDFA

Cal-IPC News Fall 2015

Hawai’i: Ground zero for plant invasions – and EMAPi13!
By Gina Darin, California Department of Water Resources and Dana Morawitz, Cal-IPC

hirty-four countries from around
the world were represented by 200
researchers, land managers, government
representatives, and students on the Big

ready for the challenge. Dave Richardson
of South Africa summarized reality best
when he suggested that “the global transplant experiment has only just begun”.

Gina and invasive “toilet bowl ginger.” Land managers gave it
this name to make the plant seem unappealing.
Island of Hawai’i this past September
for the 13th international conference on
the Ecology and Management of Alien
Plant Invasions (EMAPi13). Presenters
included three Cal-IPC Board members—
Jennifer Funk of Chapman University,
Elise Gornish of UC Davis, and Gina
Darin of the California Department of
Water Resources—as well as Cal-IPC
Program Manager Dana Morawitz.
Program session topics ranged from
the biology and ecology of invasive plants
to policy and management, and focused
mainly on environmental weed issues,
though some agricultural weeds were
addressed too. It seemed like an international Cal-IPC Symposium! Several key
themes throughout the conference were:
Global trends – Mark van Kleunen
from Germany delivered a talk on “Plant
naturalization: From global patterns to
regional and local drivers.” Regan Early
from the UK covered global prediction models and assessments of which
countries’ policies and funding levels were

Work smarter,
not harder – Kat
Shea from Penn
State University
demonstrated how
understanding disturbance regimes
leads to more
efficient management. Hillary
Cherry from
Australia talked
about incipient
attempts to use
dogs and drones to
survey for barely
detectable invad-

Abstracts may be found at www.
emapi2015.hawaii-conference.com/
program.
The field trip to Hawai’i Volcanoes
National Park included a behind-thescenes look at invasive plant strategies
and the US Forest Service biocontrol
quarantine lab in the park. We saw demonstrations of how hard it is to remove
dense stands of Hedychium gardnerianum
or “toiletbrush ginger” (renamed from
“Kahili ginger” to give it a non-Hawaiian
name with a negative connotation) and
the impacts it is having on the native
Ohia forest.
The next EMAPi conference,
EMAPi14, will be hosted by the
University of Lisbon in Portugal in
September of 2017.

ers, such as hawkweed
(Hieracium spp.), in
remote mountainous
areas of her district.
Leveraging biocontrol
was the subject of many
presentations.
Invasions on Hawai’i
– Peter Vitousek from
Stanford University
presented on “Plant
invasions and their
ecosystem-level consequences across environmental gradients” using
Hawai’i as a key example. Rhonda Loh, an
ecologist for the Hawai’i
Volcanoes National Park,
discussed how the park
prioritizes sites and sets
goals to conserve some
of every sensitive habitat
type in the park.

Water hyacinth fills a pond at Punalu’u Black Sand Beach.

Cal-IPC News Fall 2015

Habitat conservation planning and weed management

s part of the Symposium, Cal-IPC
hosted a conference track exploring
con- nections between habitat conservation plans (HCPs) and landscape-level
invasive plant management. Planning
experts from federal and state agencies
joined land managers in exploring ideas
for strengthening the connection in the
future.
HCPs are regional plans that balance
development with conservation. HCP
funding is being put toward invasive
plant management, and as more HCPs
get created, more invasive plant management work can be implemented at the
landscape-level. HCPs pay for protection
of listed species by tapping sources such
as fees on developers, tipping fees for
landfills, and fees for regional infrastructure build-out. The new HCP in Santa
Clara County is funded in part by fees
based on nitrogen deposition from vehicle
and power plant exhaust (which promotes
invasive plants in endangered butterfly
habitat).
Some funding is available from
agencies. In California, once an area has
established a Natural Areas Conservation
Plan (NCCP), the Dept. of Fish &
Wildlife has local assistance grants

available to support activities including
planning invasive plant control. Caltrans
provides advance mitigation funds for
future highway construction. At the
federal level, the US Fish & Wildlife
Service supports the Endangered Species
Act through grants for local planning and
land acquisition work; it may also be able
to fund implementation of key stewardship projects like invasive plant control.
Habitat conservation planning is
driven by local needs for both conservation and development, so it’s a situationspecific process. However, there are efforts
to standardize and streamline aspects of
the process. A national coalition of HCP
partners recently formed to support conservation work across the country. Here in
California, the state’s Biodiversity Council
(comprising all state and federal agencies
that touch on biodiversity) approved an
“Integrated Regional Conservation and
Development” planning approach. This
IRCD approach has a goal of mapping
critical resources and determining regional
conservation priorities across the entire
state in advance of setting up plans to
balance conservation and development.
Managers controlling invasive plants
on behalf of an HCP/NCCP have

developed successful strategies including:
– Maintaining a right-of-entry database
for private property where weed populations have been treated.
– Testing treatment efficacy before scaling
up to larger projects.
– Removing populations of weed species
that are a significant threat to spread even
when they are not (yet) located in prime
habitat for covered species.
– Using helicopter surveys to map weeds
efficiently over large areas.
– Engaging volunteer weed spotters as part
of an early detection program.
– Tracking restoration work in an online
database to provide a historic view.
– Preparing response actions to be used
immediately after a wildfire, both to keep
weeds from spreading and to take advantage of opportunities for weed control.
Overall there was broad agreement
at the conference that many aspects of
landscape-level invasive plant management – BMPs, prioritization, partner
coordination – are a great fit for habitat
conservation planning. We look forward
to continuing this important discussion.

Lake Forest, CA
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Cal-IPC News Fall 2015

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The WILDLAND WEED CALENDAR
California Weed Science Society
January 13-15, Sacramento
www.cwss.org

Rare Plant Survey Protocols
March 14-15, Oxnard
www.cnps.org/workshops

California Rangeland Summit
January 21-22, Stockton
www.carangeland.org

Measuring & Monitoring Rare Plant
Populations
April 4-6, Zzyzx
www.cnps.org/workshops

Tamarisk Coalition
February 9-11, Grand Junction, CO
www.tamariskcoalition.org
Western Society of Weed Science
March 7-10, Albuquerque, NM
www.wsweedscience.org

SERCAL
May 11-13, Kings Beach
www.sercal.org

California Invasive Species Action Week
June 4-12, statewide
www.wildlife.ca.gov/Conservation/Invasives/
Action-Week
Natural Areas Conference
October 21-22, Davis
www.naturalareas.org
Cal-IPC 2016 Symposium
November 2-5, Tenaya Lodge, Yosemite
www.cal-ipc.org

“Landscape-level conservation is hope-propelled rather than fear-accelerated. It’s a banding together in
the face of grave environmental threats of extinctions and degradation whose alchemy is that, by widening our horizons, the focus isn’t so much on salvage operations as on the astounding number of things
that can and need to be undertaken to restore, replenish, safeguard, protect, and celebrate the long-term
integrity of this gigantic continent’s astonishing natural and cultural heritage.”

~ Tony Hiss, from the Forward to Expanding Horizons: Highlights from the National Workshop
on Large Landscape Conservation, Washington DC, Oct. 2014. www.largelandscapenetwork.org.